"I think he's making a big mistake by not coming here and spending more time," Branstad said at an energy conference in Des Moines. "I mean Romney is dropping in the polls, and I think he wants to keep down expectations. Well, his expectations may get really bad if he doesn't get a little more serious."

Branstad said he realizes that Romney is emphasizing the New Hampshire primary, which takes place Jan. 10, a week after the Iowa caucuses.

"I know Romney is putting his focus in New Hampshire, but if he gets clobbered here — if he comes in not the top three, but say fourth or fifth — I think that really damages his campaign on the national [level]," Branstad said.

He said Romney’s advisers in Boston don’t understand the political calculus in the nation’s heartland. "They have that East Coast mentality,” Branstad said. “That was the same deal with Rudy Giuliani. At this point four years ago, he was the front-runner . . . By the time it got to Florida, he was out of it."

Romney is passing on two events in Iowa Saturday: a Christian conservative candidate forum and a birthday party fundraiser for the governor. Romney has shied away from group gatherings in Iowa during his handful of visits to the Hawkeye State this year. Instead, he generally campaigns alone for just one day.

Branstad said he's made his thoughts clear in private conversations with Romney and his aides.

"I've told key people that are close to him about this, and I've urged him to spend more time in the state," the governor said.

Asked about Branstad's comments, Romney's top Iowa adviser gave Politico nothing but praise for the governor. "He's a great governor — proud to have worked for him," said David Kochel, who was a Branstad adviser during the 1980s and 1990s.